Preparation And Properties Of Pzt Piezoelectric Fiber

Piezoelectricity is a phenomenon when a mechanical stress is applied to some piezoelectric material; electrical charges appear between its two opposite sides. Conversely, if an electrical field is applied to this material, it will generate mechanical strain. Also, for material showing Pyroelectric properties, electric charges will appear under the effect of temperature. According to these proprieties, piezoelectric ceramics have been used as sensor and actuator materials in many practical fields, especially in smart material and structural systems, because they have the ability to transform energy from electrical to mechanical and vice versa. As the application fields of piezoelectric ceramics are continuously expanding, these devices are required to be variable, both in terms of their functionality and their shape. The 1-3 connectivity piezoelectric ceramic fiber-polymer composite materials could be widely applied in smart materials and structures, since they have more toughness, performances and orthotropy.Recently piezoelectric ceramic fibers have attracted attention as regards particular applications such as in parts of 1-3 composites. In order to realize such potential applications, the fabrication of fibers is becoming an increasingly important issue. At present, the predominant fabrication route is based on the cellulose spinning process and the dice-and-fill method. Unfortunately, the cellulose spinning process can not fabricate the dense and uniform piezoelectric ceramic fibers. The dice-and-fill concept is difficult to apply to high frequency composites because of the ultrafine lateral scales required for efficient operation. Here, we describe a new technique based on the Oxide Powder in Tube (OPIT) procedure to produce ceramic fibers.First of all, PZT ceramic powders were prepared by a modified Sol-Gel method. The starting materials were lead acetate trihydrate (Pb(CH₃COO)₂·3H₂O), tetrabutyl titanate (Ti(OC₄H₉)₄), and zirconium nitrate (Zr(NO₃)₄·5H₂O. The microstructure of the nanocrystalline powder was characterized by XRD and SEM. The results show that grains of the PZT nanocrystalline powder are spherical and non-aggregated. The average grain size is 40～80nm. Compared with conventional solid reaction method, PZT powders prepared by a modified Sol-Gel method have the advantage of low temperature synthesis, stoichiometric composition precision and homogeneous distribution.Then with the PZT ceramic powder, the PZT ceramic fibers with a diameter of about 250μm were obtained by using the Oxide Powder in Tube (OPIT) procedure. The SEM morphology showed that the PZT fibers were dense and uniform. The X-ray diffraction patterns showed that the ceramic fibers were pure perovskite structure. Compared with conventional fabrication process, PZT ceramic fibers prepared by the OPIT method have the advantage of dense ,uniform and high height-to-width ratio.